Answer:
u2=19
u3=419
u4=176819
Step-by-step explanation:
when n=1
[tex]u(1 + 1) = {u1}^{2} + 3(u1) + 1[/tex]
u2= 3²+3(3)+1= 9+9+1 = 19
when n=2
[tex]u(2+ 1) = {u2}^{2} + 3(u2) + 1[/tex]
u3=19²+3(19)+1 = 361+57+1= 419
when n=3
[tex]u(3 + 1) = {u3}^{2} + 3(u3) + 1[/tex]
u4= 419²+3(419)+1 = 175561 + 1257 +1 = 176819
